Affinity interaction between EscA with CesA2, between EscA and EscL, and between EscA and EscN as demonstrated by co-elution from a Ni<sup>2+</sup>-NTA column.

<p>Experiments were carried out in a manner similar to that in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085354#pone-0085354-g003" target="_blank">Figure 3</a> with a slight modification. In essence, a His<sub>×6</sub> tag was placed at the C-terminal end of CesA2 (A), EscL (B), YgfZ (C), EscA (D), and EscN (E). Bacterial lysate containing the His<sub>×6</sub>-tagged protein was individually applied to the Ni<sup>2+</sup>-NTA column. Then bacterial lysate containing tag-free EscA (A-C and E) or CesAB (D) was applied to the column. After washing and eluting, fractions were analyzed by Western blotting with specific antibodies except that all His<sub>×6</sub>-tagged proteins were all detected by anti-His<sub>×6</sub>. I: input; F: flow through.</p>